"Magnetic resonance imaging (MRI) is a medical imaging technique used in radiology to form pictures of the anatomy and the physiological processes of the body."
A non-invasive imaging technique that uses magnetic fields and radio waves to produce detailed images of internal body structures.
Atomic structure and magnetism: Understanding the basic principles of magnetism and how they relate to the structure of atoms.
NMR spectroscopy: Understanding the fundamentals of Nuclear Magnetic Resonance (NMR) spectroscopy, which is the technique that MRI is based on.
Pulse sequences: Understanding the timing and set-up of specialized radiofrequency (RF) pulses that are used to create the images.
Image acquisition: Understanding the process of acquiring an image, which involves a series of RF pulses and their interactions with different types of tissues.
Contrast agents: Understanding how contrast agents are used to enhance the visibility of certain tissues in MRI and how they are delivered to the body.
Field strength: Understanding the relationship between magnetic field strength and image quality, and how different field strengths are used for different types of imaging.
Safety considerations: Understanding the risks associated with exposure to strong magnetic fields and radiofrequency energy, and how to mitigate those risks.
Image processing and analysis: Understanding the software and algorithms used to process and analyze MRI images.
Applications of MRI: Understanding the many different medical applications of MRI, from diagnosing cancer and cardiovascular disease to studying brain function and injury.
Future directions in MRI: Understanding emerging MRI technologies and their potential applications in medicine, such as functional MRI (fMRI) and magnetic resonance elastography (MRE).
T1-weighted MRI: This type of MRI uses repetition time (TR) and echo time (TE) to generate high-contrast grayscale images that emphasize the differences between tissues with different proton densities.
T2-weighted MRI: In this type of MRI, the TR and TE are adjusted to create bright images of tissues with high water content. This helps to highlight abnormalities like edema, inflammation, and tumors.
Diffusion-weighted MRI: This type of MRI measures the displacement of water molecules in order to detect changes in the structure of tissues. It can be particularly useful in identifying areas of ischemic stroke or malignant tumors.
Dynamic Contrast Enhancement (DCE) MRI: In this type of MRI, contrast agents are injected into the bloodstream and then tracked as they move through the body. Taking sequential scans, the data can be used to detect changes in blood flow.
Functional MRI (fMRI): This type of MRI measures changes in blood flow to different areas of the brain that occur when the brain is activated by a task. This helps researchers to identify which areas of the brain are involved in specific activities (such as speech or memory).
Magnetic Resonance Angiography (MRA): In this type of MRI, contrast agents are used to highlight blood vessels to reveal defects or blockages that might cause problems with blood flow.
Magnetic resonance spectroscopy (MRS): This type of MRI uses the same equipment as a standard MRI scan but instead of looking at images, it looks at the chemical composition of tissues. This information can help to diagnose certain types of cancer or identify anomalies in the brain.
Perfusion MRI: In this type of MRI, contrast agents are used to measure blood flow to different areas of the brain. This information can be used to identify areas of brain damage or tumors.
"MRI scanners use strong magnetic fields, magnetic field gradients, and radio waves to generate images of the organs in the body."
"MRI does not involve X-rays or the use of ionizing radiation, which distinguishes it from computed tomography (CT) and positron emission tomography (PET) scans."
"Compared to CT, MRI provides better contrast in images of soft tissues, e.g. in the brain or abdomen."
"It may be perceived as less comfortable by patients, due to the usually longer and louder measurements with the subject in a long, confining tube, though 'Open' MRI designs mostly relieve this."
"Implants and other non-removable metal in the body can pose a risk and may exclude some patients from undergoing an MRI examination safely."
"Certain atomic nuclei are able to absorb radio frequency (RF) energy when placed in an external magnetic field [...] In clinical and research MRI, hydrogen atoms are most often used to generate a macroscopic polarization."
"Hydrogen atoms are naturally abundant in humans and other biological organisms, particularly in water and fat."
"Pulses of radio waves excite the nuclear spin energy transition, and magnetic field gradients localize the polarization in space."
"While MRI is most prominently used in diagnostic medicine and biomedical research, it also may be used to form images of non-living objects, such as mummies."
"Diffusion MRI extends the utility of MRI to capture neuronal tracts in the nervous system."
"Functional MRI extends the utility of MRI to capture blood flow in the nervous system."
"The sustained increase in demand for MRI within health systems has led to concerns about cost effectiveness and overdiagnosis."
"MRI does not involve X-rays or the use of ionizing radiation."
"Compared to CT, MRI provides better contrast in images of soft tissues, e.g. in the brain or abdomen."
"Implants and other non-removable metal in the body can pose a risk and may exclude some patients from undergoing an MRI examination safely."
"Hydrogen atoms are most often used to generate a macroscopic polarization that is detected by antennas close to the subject being examined."
"Pulses of radio waves excite the nuclear spin energy transition, and magnetic field gradients localize the polarization in space."
"MRI is widely used in hospitals and clinics for medical diagnosis, staging and follow-up of disease."
"It may be perceived as less comfortable by patients, due to the usually longer and louder measurements with the subject in a long, confining tube, though 'Open' MRI designs mostly relieve this."